I. Field of the Invention
This invention relates to a hot water heating system which sometimes is referred to as a "demand hot water system" and is of the type used primarily for industrial and commercial applications for producing high volumes of hot water at a very high efficiency rate.
II. Background of the Invention
In hot water heating system of this invention, fuel is combusted to produce a flame and products of combustion are contacted directly with water to be heated to thereby achieve maximum transfer of the heat of combustion to the water resulting in extremely high efficiency. An advantage of the hot water heating system of this invention is that by directly contacting the water to be heated with the products of combustion, a higher degree of sterilization of the water is obtained, that is, a higher percentage of any entrained bacteria is killed compared to other hot water heating systems wherein a membrane, whether metal or some other material, separates the source of heat from the water itself.
A good reference to form a background of the present invention is U.S. Pat. No. 4,773,390 issued Sep. 22, 1987 and entitled "Demand Hot Water System". This patent describes a high efficiency hot water system in which fuel is combusted with the products of combustion contacting water to be heated within a water tower. The present invention includes significant improvements, refinements and innovations over the basic concept of the demand hot water system described and illustrated in this patent.
For additional background information relating to hot water heating systems of the type commonly employed in industrial and commercial applications, reference may be had to the following previously issued United States patents:
______________________________________ U.S. Pat. No. INVENTOR TITLE ______________________________________ 1820755 McMullen Method of Preparing Liquid Fuel For Burning 2218281 De Ridder et al Method For Cooling Flue Gas 2975594 Eastman Generation of Power From Ash-Forming Hydrocarbons 3183864 Stengel Method and System For Operating A Furnace 3741712 Delatronchette Supply System For A Light Hydrocarbon-Water Emulsion Burner 3749318 Cottell Combustion Method and Apparatus Burning An Intimate Emulsion Of Fuel and Water 3797992 Straitz, III Crude Oil Burner 3814567 Zink et al Smokeless Flare Using Liquid Water Particles 3860384 Vulliet et al Method To Control Nox Formation In Fossil-Fueled Boiler Furnaces 4089633 Barghout et al Combustion Vapor Generator 4089639 Reed et al Fuel-Water Vapor Premix For Low Nox Burning 4368035 McCartny et al Method and Apparatus For Heating Aggregate 4394118 Martin Method and Arrangement For Reducing Nox Emissions From Furnaces 4406610 Duijvestijn Process and Burner For The Partial Combustion of A Liquid or Gaseous Fuel 4538981 Ventrurini Combustion Catalyzing System For Commercial Grade Fuels 4634370 Chesters Flare 4773390 Watts Demand Hot Water System 5249957 Hirata Emulsion Producing Apparatus and Its Combustion System ______________________________________
In addition to these previously issued patents, the references cited against them that are not specifically enumerated hereinabove also form good background material relating to the subject of this invention.